Improved screw-cutting lathe



H. F. SHAW.

ScrewJhreading Machine.

Pafented Oct. 27, 1868.j

In Venier.

N. PErER-S, EHoTO-LIYMQGRAPHER. WASHINGTON. U C.

@anni @ffice/,-

@Ney

`HENRY r. sHAw, or WEST ROXBURY, lvilis'sAceinenTTS.` i

111mm Patent No. 83,554, dem; october 27, 186s.

MROVED SCREW-CUTTING- LATHE.

The Schedule referred to in these Lettera Patent and making part of the name.

To all whom it 'ma/y concern Be it known that I, HENRY F. SHAW, of West Roxbury, in the county of Norfolk, and State of Massaf chusetts,. have invented certain new and useful Improvements in Screw-Cutting Lathes; and I do hereby declare that the following is a full and vexact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

To enable others skilled in the art to make and use my invention, I will proceed to describe its nature, construction, and operation.

The nature of my invention consists in connecting, with the tool-carriage of a screw-cuttinglathe, a lever, which is operated by a nut running on the actuatingscrew of the lathe, the lever being so arranged, in com- 'bination with the nut of the actuating-screw, that its length may be changed at will, thus regulating the relative speed of the tool-carriage, and consequently the L is a lever pivoted to a stationary foot-piece, L. This 'lever passes freely through sockets made in the buttons K and H. 'Ihe button K is pivoted to the' screw-nut K", as shown in hg. 2, and is so arranged, in combination with the slot made in the plate Nand the screw S, fig. 2, that it may be moved up and down on I the lever L. Now, as K-is lowered, that is', brought nearer the fulcrum L', its lateral motion will cause increased motion of the upper end of its lever, L, and as the lever L passes through the button H, attached to the tool-camage `G G', the tool-cairiage will be moved with greater or less comparative rapidity, in proportion to the distance that K is from the fulcrum L'. The upper plate, N N', forms a screw-nut or nuts, through which the actuating-screw passes.

Asthe button Kis moved bythe screw S T, it may be adjusted to any point on the lever L; consequently the motion of the`tool-carriage G' G may bear any desired relation to the motion ofthe nut N. In other words, a screw of any pitch may be cut by-my improved lathe, while with screw-cutting lathes, as ordinarily arranged, only screws with a small variety of pitches can be cut.

Having thus described all that ispnecessary to make clear my invention, I will newl disclaim'a'snew any of the specific parts of the device hereinbefore described,

and state that,

What I'claim is- The arrangement, substantially as described, of the lever L, pivoted at L', the nut N having a slotted shank, N', thereon, the adjustable connecting-button K, carriage G', provided withthe swivelled and' slotted disk H, and thescrew F, or their equivalents, for the 'purpose described.

, ,HENRY F. SHAW. -Witnessesz FRANK G. PARKER, A. HUN BERRY. 

